On the phase identity and its thermal evolution of lead free (Bi1/2Na1/2)TiO3-6 mol% BaTiO3

Abstract

Articles you may be interested inElectric-field-temperature phase diagram of the ferroelectric relaxor system (1−x)Bi1/2Na1/2TiO3−xBaTiO3 doped with manganese J. Appl. Phys. 115, 194104 (2014); 10.1063/1.4876746Long ranged structural modulation in the pre-morphotropic phase boundary cubic-like state of the lead-free piezoelectric Na1/2Bi1/2TiO3-BaTiO3 J. Appl. Phys. 114, 234102 (2013) On the phase identity and its thermal evolution of lead free (Bi 1/2 Na 1/2 )TiO 3 -6 mol% BaTiO 3 Temperature-dependent dielectric permittivity of 0.94(Bi 1/2 Na 1/2 )TiO 3 -0.06BaTiO 3 (BNT-6BT) lead-free piezoceramics was studied to disentangle the existing unclear issues over the crystallographic aspects and phase stability of the system. Application of existing phenomenological relaxor models enabled the relaxor contribution to the entire dielectric permittivity spectra to be deconvoluted. The deconvoluted data in comparison with the temperature-dependent dielectric permittivity of a classical perovskite relaxor, La-modified lead zirconate titanate, clearly suggest that BNT-6BT belongs to the same relaxor category, which was also confirmed by a comparative study on the temperature-dependent polarization hysteresis loops of both materials. Based on these results, we propose that the low-temperature dielectric anomaly does not involve any phase transition such as ferroelectric-toantiferroelectric. Supported by transmission electron microscopy and X-ray diffraction experiments at ambient temperature, we propose that the commonly observed two dielectric anomalies are attributed to thermal evolution of ferroelectric polar nanoregions of R3c and P4bm symmetry, which coexist nearly throughout the entire temperature range and reversibly transform into each other with temperature.

Quenching-induced circumvention of integrated aging effect of relaxor lead lanthanum zirconate titanate and (Bi1/2Na1/2)TiO3-BaTiO3

“…%BaTiO 3 (BNT-6BT). 16 The same set of ceramic samples with those reported in Ref. 16 was employed for a systematic quenching experiments.…”

Enhanced piezoelectricity and nature of electric-field induced structural phase transformation in textured lead-free piezoelectric Na0.5Bi0.5TiO3-BaTiO3 ceramics

“…While the orthorhombic phase is proposed to have an antiferroelectric (AFE) characteristic, 17,18 recent studies instead describe it as a relaxor phase with polar nanoregions. 19,20 The high piezoelectric response and E-field induced strain in NBT based systems has been attributed to structural phase transitions under the application of E-field. [21][22][23] Similar to NBT-BT systems, NBT-KBT (Ref.…”

The influence of Mn substitution on the local structure of Na0.5Bi0.5TiO3 crystals: Increased ferroelectric ordering and coexisting octahedral tilts

“…2 Furthermore, recent investigations of Na 1/2 Bi 1/2 TiO 3 -xat.%BaTiO 3 (NBT-x%BT) have revealed giant strain and longitudinal piezoelectric constants as high as d 33 ¼ 500 pC/N for compositions near a morphotropic phase boundary (MPB) around x ¼ 5.5-6.5. [3][4][5][6][7][8][9][10][11][12][13] In spite of a non-rhombohedral average structure model for NBT at room temperature was supported by highresolution single-crystal x ray diffraction, 14 it is still widely accepted that NBT undergoes a phase transformational sequence of paraelectric cubic (C) ! paraelectric tetragonal (T) !…”